In communication networks, such as Internet Protocol Multimedia Subsystem networks, communication sessions are routed through a communication network from an originating device (e.g., a voice over internet protocol telephone and/or public switched telephone network telephone) to a terminating device (e.g., a voice over internet protocol telephone and/or a public switched telephone network telephone). If the terminating device is busy or a communication session between the originating device and the terminating device is not initiated, the communication session is transferred to a voicemail mailbox associated with the terminating device at a voicemail server. The originating device then has an opportunity to leave a message (e.g., a voice message) in the voicemail mailbox.